The crews of the International Space Station and space shuttle Atlantis celebrated the opening of the station's new European-built science laboratory Tuesday.

Crew members set up electrical and data lines linking the Columbus laboratory to the station before European astronaut Leopold Eyharts briefly floated inside the module for the first time.

Two Atlantis astronauts conducted a spacewalk Monday to install the laboratory, with help from crewmates inside the ISS.

Two Atlantis astronauts will conduct a second spacewalk Wednesday, to install a new nitrogen tank on the orbital outpost. One of the spacewalkers, Germany's Hans Schlegel, was forced to pull out of Monday's activity because of an undisclosed illness. But he told reporters Tuesday he was feeling good enough to conduct Wednesday's spacewalk.

Earlier Tuesday, officials for the U.S. space agency NASA told the shuttle crewmembers they would not have to repair a loose thermal blanket near the shuttle's tail, saying the blanket does not pose a flight safety issue.